Vaccine approach offers hope for kidney cancer
NEW YORK, Mar 01 (Reuters Health) --
Study findings suggest that a vaccine designed to target cancer
cells may offer hope to patients with advanced kidney cancer, a
disease that currently carries a grim prognosis.
Researchers in Germany found that a vaccine made from a patient`s
own cancer cells could fight advanced kidney cancer, tumors that had
spread to other organs. In a study of 17 patients dying of the
disease, seven responded to the treatment, including four who went
into complete remission. Dr. Alexander Kugler of the University of
Gottingen and his colleagues report the study results in the March
issue of Nature Medicine.
Once kidney cancer spreads to other sites, such as the liver,
lungs, and bones, it is "nearly impossible" to treat with
conventional approaches like chemotherapy, according to Dr. Donald
W. Kufe of the Dana-Farber Cancer Institute in Boston,
In an interview with Reuters Health, Kufe said that the German
study was the first clinical application of a cancer-vaccine
approach he and other researchers have used in animal models. These
vaccines consist of cancer cells that are fused with immune system
cells called dendritic cells.
Vaccine therapy for cancer is based on the same premise as are
disease-preventing vaccines: exposing the immune system to a foreign
invader, or antigen, teaches it to recognize and destroy the
antigen. Since tumor cells contain antigens, vaccine therapy aims to
train the immune system to fight the cancer.
The dendritic cells used in the current study`s vaccine are
antigen-presenting cells -- they display antigens on their surfaces
to make them easier targets for the immune system`s killer cells.
Recent research has shown that dendritic cells "are the best kind of
antigen-presenting cells," Kufe said, adding that they are currently
the "hot topic" in vaccine-therapy research.
In the German study, Kugler`s team electrically fused tumor cells
with dendritic cells to create the vaccine -- theoretically, the
dendritic cells should present the proteins on the tumor cells to
the immune system, stimulating an attack. Patients received one
injection, followed by a booster 6 weeks later. If their disease did
not progress, they continued to get boosters every 3 months.
After up to 21 months of follow-up, four patients were in
complete cancer remission, two were in partial remission, and one
patient showed regression of the kidney tumors, but progression in
tumors that had spread to bone. Eight of the 17 patients died or saw
their cancer progress. No patients suffered a serious side effect
from the vaccine.
Despite the number of patients who were not helped, the success
of this study`s cancer vaccine is "unprecedented," according to
Kufe. Once kidney cancer has spread to other organs, he said, fewer
than 10% of patients respond to current therapies, and most die
within months. The study results should also spur research into
treating other cancers with similar vaccines, he noted.
If longer follow-up and future research confirm the current
findings, Kufe said, the vaccine would initially be used following
surgery in patients whose cancer had spread extensively. Considering
the lack of treatment options for advanced kidney cancer, he added,
vaccine therapy could become the first-line treatment.
SOURCE: Nature Medicine 2000;6:252-253, 332-336.